Caseless cartridge firing mechanism

ABSTRACT

A caseless cartridge firing mechanism which uses a novel spring seal to seal the firing chamber. By virtue of a spring preload against the surface to be sealed, a pressure differential is built up between the sealing surfaces and creates the sealing force.

Unite States atent [191 Shum, Jr. et ai. 1March 20, 1973 CASELESSCARTRIDGE FIRING [56] References Cited MECHANISM UNITED STATES PATENTS[75] Inventors: John Shum, Jr., Valley Station, Ky.;

Dean R. K l C H. 2,993,412 7/1961 Goldsmith ..89/1.80l both of Marion m3,534,895 10/1970 Henning ..227/10 7 3,296,728 1/1967 Kuavle ..42/l R[73] Assignee; Olin Corporation, N w Hav 1,897,992 2/1933 Ailes ..42/l GConn. Primary Examiner-Samuel W. Engle Flledi May 1971 Attorney-D0naldR. Motsko, H. Samuel Kiser and 21 Appl.No.: 140,856 wllllam w-lones 157ABSTRACT [52] US. Cl. ..42/l R, 42/2, 89/1 B,

39/26 A caseless cartridge firing mechanism WhlCh uses a 51 Int. Cl...F41j 1/00 novel Spring Seal to Seal the firing chambery virtue 58Field of Search ..42/1, 9, 2; 129/7, 1; 60/26.1; of a Spring preloadagainst the surface to be sealed, a 227/9, 10, 11 pressure differentialis built up between the sealing surfaces and creates the sealing force.

1 1 Claims, 4 Drawing Figures PATENTEDMARZO I913 SHEET 1 [IF 2 CHAO H.u/v JUHN SHUM JR. DEAN R. K/LBOURN INVENTORS BY Mi t-J4 ATTORNEYCASELESS CARTRIDGE FIRING MECHANISM This invention concerns a mechanismfor firing a caseless charge of propellant in the form of a pellet orthe like, wherein a preloaded spring seals the firing chamber with thesealing force being increased by a pressure differential built upbetween the spring and the surface to be sealed when the charge isfired.

The use of caseless propellant charges such as pellets or the like ofcompacted nitrocellulose has recently become the subject of renewedinterest for firing firearms, power-actuated tools, and other suchdevices operated by high pressure combustion gases. Most of thetechnology for sealing the firing chambers of devices using caselesscharges or pellets is still relatively new. The problems in sealing thegases generated by the caseless charge are vastly different than thoseencountered in sealing a cased or obturated charge such as a brasscartridge, since the cartridge casing itself provides the majority ofthe obturating function. The prior art relating to the sealing ofcaseless pellets dis closes the bolt action principle wherein a boltmechanism cams two halves together with a separate seal to effect a gasseal. One basic disadvantage of the bolt action is that the size of themechanism can become a problem if available space is limited. The twohalves must separate to load the charge and axial movement of one of thehalves relative to the other must occur. The force needed to cam the twohalves together is quite large and can present a problem if doneremotely. It has been found that elastomeric, labyrinth or other sealsare generally required in conjunction with a boltactuated caselesscharge device.

To overcome these disadvantages, the mechanism of this inventionutilizes a spring-type seal which is mounted on a rotor containing thefiring chamber. The rotor and spring seal are mounted for rotationalmovement in a housing having a bore for this purpose. The spring seal isin the form of a curved spring blade having an outer diameter which islarger than the diameter of the housing bore in which it is disposed.The spring blade includes a gap which permits the blade to be compressedfor insertion into the housing bore so that once inserted into thehousing bore, the spring blade will flex outwardly into snug engagementwith the wall of the housing bore. The rotor is disposed inside of thehousing bore and inside of the spring, and the rotor has an opening inits side wall which communicates with the firing chamber. A pair of pinsare secured to the rotor and extend outwardly therefrom into the springgap, the pins serving to align the spring gap with the rotor opening,and also serving to cause the spring to rotate conjointly with therotor. The housing also includes a pellet feed inlet, and a combustiongas outlet which intersect the housing bore and extend radiallyoutwardly therefrom. The inlet and outlet are angularly spaced apartfrom each other in such a manner that the rotor opening and spring gapcan both be moved into selective alignment with either the inlet or theoutlet. An operating handle is provided for rotating the rotor betweenthe inlet and outlet, so that when the rotor opening and spring gap arealigned with the inlet, a caseless pellet can be fed into the firingchamber. The rotor is then rotated so that the rotor opening and springgap are aligned with the outlet and the pellet is then fired to producehigh pressure combustion gases which pass through the outlet. The devicecan be used with any apparatus which uses high pressure gases to dowork, as for example, with a firearm, a power-actuated tool, or thelike.

It is, therefore, an object of this invention to provide a caselesspellet firing mechanism which operates without longitudinal movementoccurring between the chamber sealing members.

It is a further object of this invention to provide a caseless pelletfiring device of the character described wherein a spring member isprovided to seal the firing chamber.

It is still another object of this invention to provide a caselesspellet firing device of the character described wherein rotary movementis used to load and position a pellet for firing.

These and other objects and advantages of this invention will be readilyapparent from the following detailed description and accompanyingdrawings, in which:

FIG. 1 is an exploded perspective view of a preferred embodiment of themechanism of this invention;

FIG. 2 is a side perspective view of the mechanism of FIG. 1 shown asassembled;

FIG. 3 is a side sectional view of the device taken along line A-A ofFIG. 2; and

FIG. 4 is a sectional view of the device taken along line B-B of FIG. 3.

Referring now to FIG. 1, the device includes a housing 2 having a firstbore 4 which intersects a second bore 6 (see FIG. 4) at substantiallyright angles. The second bore 6 is an outlet for high pressurecombustion gases formed when the pellet is fired, and is threaded as at8 for connection to a related device which uses the combustion gases todo work. For example, the housing 2 may be connected to a barrel forfiring a projectile, or a fastener, as in a firearm or power-actuatedtool, or may be connected to a cylinder for driving a piston or thelike. A port 10 is formed through the wall of the housing 2, the port 10intersecting the bore 4 to form a passage through which pellets may beloaded into the device. The outer end of the bore 4 is enlarged andthreaded as at 12 for a purpose more clearly set forth hereinafter. Ahollow rotor 14 having a first enlarged portion 16 and a second reducedportion 18 separated by a shoulder 20 is rotatably mounted in the bore4. The diameter of the shoulder 20 is substantially the same as thediameter of the bore 4 with the diameter of the enlarged portion 16being somewhat smaller than the diameter of the bore 4. A pellet feedopening or slot 22 is cut through the wall of the enlarged portion andcommunicates with the interior of the rotor 14. A seal in the form of aspring member 24 is positioned around the exterior of the enlargedportion 16 of the rotor. The spring member 24 is in the form of anannular sheet of spring material, preferably spring steel, with anoutside diameter which is slightly greater than the diameter of the bore4, and with an inside diameter which is slightly greater than theoutside diameter of the enlarged portion 16 of the rotor. Thelongitudinally extending end surfaces 26 and 28 of the spring 24 arespaced apart to form a longitudinal gap 30 in the spring 24 whichpermits the latter to be compressed to reduce the outside and insidediameters thereof and put the spring in a state of stress. In order tomount the spring 24 on the rotor 14, the spring 24 is slipped over theenlarged portion 16 of the rotor 14 and then compressed to reduce thesprings outside diameter. The rotor 14 and compressed spring 24 are theninserted into the bore 4 where the spring 24 tries to assume itsoriginal dimensions. Thus the spring 24 is biased into snug engagementwith the wall of the bore 4. A pair of pins 32 and 34 are mounted on theenlarged portion 16 of the rotor 14 and extend outwardly therefrom toengage the end surfaces 26 and 28 on the spring 24. The pins 32 and 34keep the gap 30 and the slot 22 aligned and cause the spring 24 torotate conjointly with the rotor 14. A plug 36 is fitted into the bottomof the bore 4 to close off the inner end of the interior of the rotor14.

A sleeve 38 is threaded into the counterbore l2 and thus secured to thehousing 2. The sidewall of the sleeve 38 includes a transverse slot 40and a pair of Iongitudinally extending similar slots 42 (one of which isshown), the latter being spaced preferably 180 apart on the sleeve. Theslots 42 are formed with a transverse extension 44 which defines ashoulder 46. A camming surface 48 is positioned opposite the extension44. An operating handle 50 having a threaded end portion 52 extendsthrough the slot 40 and is screwed into a threaded port 54 formed on anannular collar 56 which is mounted on the reduced portion 18 of therotor 14. The threaded end 52 of the handle 50 extends through thecollar 56 and is screwed tightly against a flat 58 formed on the reducedportion 18 of the rotor 14, thus the collar 56 and rotor 14 are lockedtogether. The collar 56 is positioned within the sleeve 38 and includesa pair of notches 60 each of which is bounded on one side by an inclinedcamming surface 62 and 64, and on the other side by a surface 66 whichis contained in a plane parallel to the axis of the collar. It is notedthat longitudinally extending projections 68 and 70 are formed at oneend of the camming surfaces 62 and 64, and laterally extendingprojections 72 are formed at the corresponding end of the surface 66.

A firing pin 74 is mounted in the interior of the rotor 14, it beingnoted that the interior of the rotor 14 includes an enlarged bore 76defining a firing chamber, and a reduced bore 78 in which the firing pin74 is slidably mounted (see FIG. 3). The firing pin 74 is threaded as at80 and a disc 82 having a threaded aperture 84 is screwed on to thefiring pin. The disc 82 includes a pair of projecting ears 86 which arepositioned in the slots 42 and which extend through the collar notches60.

A cap 88 is screwed into the sleeve 38 to close one end thereof and acompressible spring member 90 is positioned within the cap 88 and incontact with the disc 82 to bias the firing pin 74 toward the firingchamber 76.

Referring now to FIGS. 2-4, it will be noted that the spring 24 isstressed against the wall of the bore 4 so that when the pellet feedslot 22 and spring gap 30 are aligned with the outlet port 6, the spring24 seals the loading port from the firing chamber 76. Also when the slot22, the gap 30, and the outlet port 6 are aligned, the firing pin 74 isdisposed in its fired position under the influence of the spring 90.

The device operates in the following manner. As mentioned above, FIGS. 2and 3 show the fired condition of the device wherein the firing chamber76 is empty. In this condition the operating handle 50 is positioned atthe intersection of the slots 40 and one of the slots 42, and the discears 86 are positioned at the ends of the slots 42 nearest the housing2. In order to load the device and cock the firing pin, the handle 50 ismoved through the slot 40 to the position 50 shown in phantom in FIG. 2.This causes the collar 56 and the rotor 14 to rotate within the sleeve38. The pins 32 and 34 cause the spring 24 to rotate conjointly with therotor 14. When the handle is in the position 50, the rotor slot 22 andspring gap 30 are disposed in alignment with the pellet loading port 10so that a propellant pellet can be inserted into the firing chamber 76through the port 10. As the collar 56 rotates, the cam surfaces 62 and64 move against the disc ears 86 and force the latter to slide throughthe slots 42 toward the camming surfaces 48. Thus the disc 82 andattached firing pin 74 move away from the firing chamber 76 and compressthe spring 90. The cars 86 move against the camming surfaces 48 and withthe aid of the projections 68 and 70, are cammed over and onto theshoulders 46 when the handle reaches the position 50'. In this mannerthe firing pin 74 is cocked at the same time that the device is loaded.To fire the device, the handle 50 is moved from the position 50' back tothe position shown in FIG. 3 to rotate the rotor slot 22 and the springgap 30 back into alignment with the outlet bore 6 and to seal theloading port 10. The return of the handle 50 to the position shown inFIG. 3 causes the collar 56 to rotate back until the projections 72thereon engage the disc ears 86 and push the latter off of the shoulders46. The spring is then free to drive the disc 82 and firing pin 74toward the firing chamber 76 where the firing pin 74 strikes thechambered pellet (not shown) causing the latter to burn. Thus reciprocalmovement of the handle 50 serves to permit loading of a pellet, cocksthe firing pin, and fires the device. It is noted that, while a firingpin mechanism has been disclosed as the preferred mode for firing apellet, any other firing mechanism such as a hammer or electricaligniter may be used in conjunction with the spring seal of thisinvention without departing from the spirit of the invention.

Tests of the firing mechanism have produced approximately 1,800 lbs. ofsealing force with 12,000 psi chamber pressure using primed impactignition caseless pellets of compacted nitrocellulose. It is readilyapparent that the invention offers the metal to metal sealing advantagesof a cased round for firing caseless ammunition. The device is ofcompact, simple construction and operates without the need of complexlabyrinth seals or nondurable elastomeric seals. Furthermore, the firingmechanism can be used with any number of related structures whichutilize high pressure combustion gases to do work, such as firearms,power-actuated tools, or the like.

We claim:

1. A firing mechanism for caseless ammunition, said mechanismcomprising:

a. a housing having a first bore and a loading port communicating withsaid first bore;

'b. rotor means mounted in said first bore, said rotor means beinghollow to define a firing chamber and having an opening communicatingwith said firing chamber, said rotor means being rotatable between afirst position wherein said opening is aligned with said loading port,and a second position wherein said opening is angularly offset from saidloading port;

c. sheet-like spring means mounted on said rotor means for conjoinmovement therewith, said spring means being in stressed engagement witha wall of said first bore and operative to seal said firing chamber fromsaid loading port when said rotor is in said second position;

d. a firing pin slidably mounted in said rotor and movable between acocked position and a fired position;

/ eecoil spring means operative to bias said firing pin toward saidfired position;

f. camming means mounted on said rotor and conjointly rotatabletherewith, said camming means being operable to move said firing pin tosaid cocked position when said rotor is moved to its first position; and

g. means operable to retain said firing pin in its cocked position.

2. A firing mechanism for caseless ammunition, said mechanismcomprising:

a. a housing having a first bore and a loading port communicating withsaid first bore; rotor means mounted in said first bore, said rotormeans providing a firing chamber, said rotor means being rotatablebetween a first position wherein said firing chamber is open to saidloading port, and a second position wherein said firing chamber isangularly offset from said loading port; c. fiat spring means having anarcuate crosssection and mounted on said rotor for conjoint movementtherewith, said spring means being in stressed engagement with a wall ofsaid first bore and operative to seal said firing chamber from saidloading port when said rotor is in said second position;

. sleeve means secured to said housing and coaxial with said first bore,said sleeve means having a first circumferential slot, and at least onelongitudinal slot;

e. a firing pin slidably mounted in said rotor and movable between acocked position and a fired position;

f. disc means secured to said firing pin, said disc means having atleast on lateral extension slidably disposed in said longitudinal sleeveslot;

g. collar means secured to said rotor means and rotatable conjointlytherewith, said collar means having at least one camming surfaceengageable with said disc lateral extension and operable when saidcollar means is rotated in a predetermined direction, to slide saidlateral extension through said longitudinal slot to cock said firingpin; and

h. spring means operable to bias said firing pin toward its firedposition.

3. The mechanism of claim 2, further comprising shoulder means formed onsaid longitudinal slot and operative to engage said lateral extension todetain said firing pin in said cocked position.

4. The mechanism of claim 3, further comprising means formed on saidcollar operative to dislodge said lateral extension from engagement withsaid shoulder means to fire the mechanism.

5. The mechanism of claim 2, further comprising an operating handlesecured to said collar means and extending outwardly through saidcircumferential slot.

6. A firing mechanism for caseless ammunition, said mechanismcomprising:

a. a housing having a bore and a loading port communicating with saidbore;

b. rotor means mounted in said bore, said rotor means being hollow todefine a firing chamber and having an opening communicating with saidfiring chamber, said rotor means being rotatable between a firstposition wherein said opening is aligned with said loading port and asecond position wherein said opening is angularly offset from saidloading port;

c. springy seal means operative to seal said firing chamber from saidloading port when said rotor is in said second position;

d. a firing pin slidably mounted in said rotor and movable between acocked position and a fired position;

e. spring means operative to bias said firing pin toward said firedposition; and

f. camming means mounted on said rotor and conjointly rotatabletherewith, said camming means being operable to move said firing pin tosaid cocked position when said rotor is moved to said first position.

7. The mechanism of claim 6, further comprising means operative toretain said firing pin in said cocked position.

8. A firing device for caseless ammunition, said device comprising:

a. a housing having a bore formed therein and a loading portcommunicating with said bore;

b. means mounted in said housing providing a firing chamber accessablethrough said loading port whereby a round of caseless ammunition can beinserted into said firing chamber through said loading port;

c. a sheet-like annular metal member with substantial inherentresiliency mounted in said bore between said port and said firingchamber, said member being in an internally stressed condition so as tobe biased into snug engagement with the wall of said bore, and saidmember being movable from a first position exposing said firing chamberto said port to a second position covering said port; and

d. means operative to ignite a round of caseless ammunition disposed insaid firing chamber.

9. The device of claim 8 wherein said annular metal member is aninterrupted sleeve of spring steel having an outside diameter which,when the sleeve is in an unstressed condition, is somewhat larger thanthe diameter of said bore.

10. A firing mechanism for caseless ammunition, said mechanismcomprising:

a. a housing having a first bore, a second bore communicating with saidfirst bore, and a loading port communicating with said first bore;

b. a rotor mounted in said first bore, said rotor having a hollowinterior defining a firing chamber, and an opening in said rotorcommunicating with said firing chamber, said rotor being rotatablebetween a first position wherein said opening is aligned with saidloading port, and a second position wherein said opening is aligned withsaid second bore;

. a sheet-like annular metal member with substantial means operative toignite a round of'caseless ammunition in said firing chamber.

11. In a firing mechanism for caseless ammunition, the mechanismincluding a housing, a firing chamber disposed in the housing, a loadingport communicating with the firing chamber, and means operative toignite a round of caseless ammunition in the firing chamber, theimprovement comprising: a movably mounted sheet-like annular inherantlyresilient metal member interposed between said firing chamber and saidloading port, said member being in an internally stressed condition soas to be biased into snug engagement with the periphery of said loadingport to seal the firing chamber from the loading port; and means formoving said member into and out of said biased snug engagementwith theperiphery of said loading port.

1. A firing mechanism for caseless ammunition, said mechanismcomprising: a. a housing having a first bore and a loading portcommunicating with said first bore; b. rotor means mounted in said firstbore, said rotor means being hollow to define a firing chamber andhaving an opening communicating with said firing chamber, said rotormeans being rotatable between a first position wherein said opening isaligned with said loading port, and a second position wherein saidopening is angularly offset from said loading port; c. sheet-like springmeans mounted on said rotor means for conjoin movement therewith, saidspring means being in stressed engagement with a wall of said first boreand operative to seal said firing chamber from said loading port whensaid rotor is in said second position; d. a firing pin slidably mountedin said rotor and movable between a cocked position and a firedposition; e. coil spring means operative to bias said firing pin towardsaid fired position; f. camming means mounted on said rotor andconjointly rotatable therewith, said camming means being operable tomove said firing pin to said cocked position when said rotor is moved toits first position; and g. means operable to retain said firing pin inits cocked position.
 2. A firing mechanism for caseless ammunition, saidmechanism comprising: a. a housing having a first bore and a loadingport communicating with said first bore; b. rotor means mounted in saidfirst bore, said rotor means providing a firing chamber, said rotormeans being rotatable between a first position wherein said firingchamber is open to said loading port, and a second position wherein saidfiring chamber is angularly offset from said loading port; c. flatspring means having an arcuate crosssection and mounted on said rotorfor conjoint movement therewith, said spring means being in stressedengagement with a wall of said first bore and operative to seal saidfiring chamber from said loading port when said rotor is in said secondposition; d. sleeve means secured to said housing and coaxial with saidfirst bore, said sleeve means having a first circumferential slot, andat least one longitudinal slot; e. a firing pin slidably mounted in saidrotor and movable between a cocked position and a fired position; f.disc means secured to said firing pin, said disc means having at leaston lateral extension slidably disposed in said longitudinal sleeve slot;g. collar means secured to said rotor means and rotatable conjointlytherewith, said collar means having at least one camming surfaceengageable with said disc lateral extension and operable when saidcollar means is rotated in a predetermined direction, to slide saidlateral extension through said longitudinal slot to cock said firingpin; and h. spring means operable to bias said firing pin toward itsfired position.
 3. The mechanism of claim 2, further comprising shouldermeans formed on said longitudinal slot and operative to engage saidlateral extension to detain said firing pin in said cocked position. 4.The mechanism of claim 3, further comprising means formed on said collaroperative to dislodge said lateral extension from engagement with saidshoulder means to fire the mechanism.
 5. The mechanism of claim 2,further comprising an operating handle secured to said collar means andextending outwardly through said circumferential slot.
 6. A firingmechanism for caseless ammunition, said mechanism comprising: a. ahousing having a bore and a loading port communicating with said bore;b. rotor means mounted in said bore, said rotor means being hollow todefine a firing chamber and having an opening communicating with saidfiring chamber, said rotor means being rotatable between a firstposition wherein said opening is aligned with said loading port and asecond position wherein said opening is angularly offset from saidloading port; c. springy seal means operative to seal said firingchamber from said loading port when said rotor is in said secondposition; d. a firing pin slidably mounted in said rotor and movablebetween a cocked position and a fired position; e. spring meansoperative to bias said firing pin toward said fired position; and f.camming means mounted on said rotor and conjointly rotatable therewith,said camming means being operable to move said firing pin to said cockedposition when said rotor is moved to said first position.
 7. Themechanism of claim 6, further comprising means operative to retain saidfiring pin in said cocked position.
 8. A firing device for caselessammunition, said device comprising: a. a housing having a bore formedtherein and a loading port communicating with said bore; b. meansmounted in said housing providing a firing chamber accessable throughsaid loading port whereby a round of caseless ammunition can be insertedinto said firing chamber through said loading port; c. a sheet-likeannular metal member with substantial inherent resiliency mounted insaid bore between said port and said firing chamber, said member beingin an internally stressed condition so as to be biased into snugengagement with the wall of said bore, and said member being movablefrom a first position exposing said firing chamber to said port to asecond position covering said port; and d. means operative to ignite around of caseless ammunition disposed in said firing chamber.
 9. Thedevice of claim 8 wherein said annular metal member is an interruptedsleeve of spring steel having an outside diameter which, when the sleeveis in an unstressed condition, is somewhat larger than the diameter ofsaid bore.
 10. A firing mechanism for caseless ammunition, saidmechanism comprising: a. a housing having a first bore, a second borecommunicating with said first bore, and a loAding port communicatingwith said first bore; b. a rotor mounted in said first bore, said rotorhaving a hollow interior defining a firing chamber, and an opening insaid rotor communicating with said firing chamber, said rotor beingrotatable between a first position wherein said opening is aligned withsaid loading port, and a second position wherein said opening is alignedwith said second bore; c. a sheet-like annular metal member withsubstantial inherant resiliency sandwiched between said rotor and theadjacent wall of said first bore, said member being in an internallystressed condition so as to be biased into snug engagement with the wallof said first bore, said member being conjointly movable with saidrotor, and said member including a gap aligned with said rotor opening,said member being operative, by virtue of its snug engagement with saidwall of said first bore, to seal said loading port from said firingchamber when said rotor is in said second position; and d. meansoperative to ignite a round of caseless ammunition in said firingchamber.
 11. In a firing mechanism for caseless ammunition, themechanism including a housing, a firing chamber disposed in the housing,a loading port communicating with the firing chamber, and meansoperative to ignite a round of caseless ammunition in the firingchamber, the improvement comprising: a movably mounted sheet-likeannular inherantly resilient metal member interposed between said firingchamber and said loading port, said member being in an internallystressed condition so as to be biased into snug engagement with theperiphery of said loading port to seal the firing chamber from theloading port; and means for moving said member into and out of saidbiased snug engagement with the periphery of said loading port.